Flexible shafting



May 25, 19472- y c. F. HorcHKlss, JR 2,284,090 Y.

FLEXIBLE-SHAFTING Filed Nov. 24, 1Q41 ..5 m. ,NN

4 afina?! VA/l SIMM/"Ws,

Patented May 26, 1942 e 2,284,090 FEXYIBLE SHAFTING Clarence F; Hotchkiss, Jr., Binghamton, N.- Y., as signor tov Stow? Manufacturing Company,V Inc.,

Binghamton, N. Y.

'Application November 24, 1941, serai No. 120,289

(ci. ,25a-i1),

al claims.

- This invention rrelates to flexiblev shafting and more particularly to the driven endfof the exible shafting and itsk cooperating fitting with. a4 member to be rotated' thereby.

The primary object of the invention is to min' imize or prevent.v thevterric wear on the flexible shafting when used toV drive a concrete vibrator by reason of its throw or contact with the conventional outer casing normally positioned around the shafting.

An object ofthe invention, is Yto provide an improved driving means for concrete vibrators, plastic compactors or vsimilar instrumentalities by means of a driven flexible shaft offthe type formed from a spirally wound wire positioned in an outer metal casing. Thisl broad'combination has been used. for many years, butwhengdriving su-ch toolsA or devices, the exible shafting is projected, by the eccentric action of the .vi-brator at a point near its driving'end in. suchfa manner that the spiral' coil of theshaf-ting` strikes the outer casing and rapidly deteriorates the shafting. Y

The present invention has particular application in driving concrete compactors of the type using eccentrically mounted or offset weights attached to a driven spindle, as. vibrators or compactors of this class create vibration of such magnitude that theexible shafting is 'rapidly worn out adjacentthe end of the shafting pro-v truding from the casing and attached to the vibrator spindle'.

The salient feature, therefore, of this invenof the flexible shaft so that it will lie in offset lateral alignment with the normal longitudinal axis of the device to be rotated.

In the' drawing( Figure 1 is a longitudinal- View, mostly in section of a conventional vibrator with the exibleV shaft affixed centrally of the vibrator spindle and showing the position assumed by the shaft when it is rotated.

Figure 2 is an enlarged vertical section of the coupling portion of the flexible shaft and vibrator and spindle of this improvement showing the exible shaft at rest and in dotted lines the position assumed when rotated.

Figureis a cross sectionalview taken on lineV 3`3 ofv FigureI 1 showinga conventional form of the, eccentric weight whose rotation creates the Wear on the flexibljshaft. l 7

Figure 4 discloses `the 'exib'le shaft end fitting cou-pled? with the vibratorL spindle in nonaxial alignment therewith.

FigureV 5 isA a modification showing the shaft fitting mounted eccentrically in the vibrator spindle; d

' Figuref isv a vertical section taken on line 6 6 of Figure 5; y Y ,.7

Figure 7 is aj modification showing the flexible shafting per se mounted in an obliquek bore in the shaftvfitting; v

Figure 8 is'a vertical sectiontaken'on line 8*-,8V of Figure '7.v Q

vFigure 9- isa further modification showing the flexible shafting terminating inan eccentrically positioned bore in the shaft fitting. f

As before stated, the crux of this invention is the distorting or positioning ofthe driven end of a iexilole` shaft with relation to the, member to be rotated so that it willv not be Worn and damaged bycontact withV the metal of theA enveloping casing Whichis positionedv aroundl the flexible shaft from its driving en d fitting to the drivenend-'which is coupled with a suitable-source of rotating power.- y

Ordinarily in concrete Compactors the flexible -sha-fting immediatelyl adjacent'the end'fitting,

contacts andl rubs against the inner surface of the outer protective casing'toA such an extent that the flexible shafting is rapidly worn and seriously damaged. Thus, in ordinary practice, flexible shaftings used for driving concrete vibrators will only stand up for a comparatively few hours whenthey; must be replacedv at aV considerable money lossf and expenditure of labor. .By com-A pensating for this initial swing out orcentrifugal action ofthe flexible shaft yadjacent its'driven end, the wearing'out of the flexible shaftingA is practically eliminated and, by following the `teachings of this invention, the life of flexible shafts for driving concrete vibrators has beenincreased many fold.

To more fully explain and illustrate the invention, Figure 1 of the accompanying drawing illustrates a conventional concrete vibrator having the usual centrally and axially aligned fiexible shaft for rotating the eccentric or offset 2- f l .t Y Y 2,284,090

weight. When the iiexible shaftlng is at rest, it extends centrally of its outer casing in a straight line but when rotated at a high speed, it is thrown out of alignment and strikes the casing as shown in both full and dotted lines. Here, numeral I denotes a rotary shaft or spindle mounted in suitable ball bearings 2 and carrying one or more eccentrically Positioned weights 3 keyed onto 'the rotary spindle, the vibrator being mounted in a shell 4. This particular apparatus merely shows one type of concrete compacter in which the` present invention has met with startling success.-

The spindle I is provided with a" central axial d bore 5 within which is mounted the shaft tting or tip 6 having a socket 'I and mounted in 'fixedrelation therewith through the medium of a kei7 or spline 8.

l The flexible shaft I0 is, asfar 'as structure.;

more or less conventional and consists of one or more layersof spirally wound wire. 'I'he shaft is protected by a suitable flexible casing II made up of one or more metallicspiral members II,v and the interior diameter thereofv is such that it does not bind the exiblegshaft-II). I-Iowever, whenrotated at high speed, the portion ofthe flexible shafting near the driven end and vordinarily Within a distance of 2 tor8y inches of the end Vfitting generates an outward swing or bulge4 y probably due to a combined eccentric and centrifugal action, and this Vportionof the shafting strikes or rubs theV metal of the outer casing with enough force to rapidly wear lthe shaft winding. This eccentric or whip action assumed by the driven flexible shaft is illustratedin'Figure 1 where the shaft isshown thrown against the interior of the spiral casing II`. 'y Y Y Y To overcome this tendency andthe outward wear, the present invention was developed. after considerable experimentation and labor and broadly, the inventionrconsists in distorting the shafting to place it out of true axial alignment with the driven spindle or to Vmount the fitting within the spindle or the flexbleshafting within the fitting socket in nonaxial alignment with these parts to compensate orovercome the tendency of the flexible shaft to move outwardly and wear against the inner surface of theouter casing. During extendedtests withconventionally positioned shafting, the end portion'of vthe shafting near the vfitting shows ay distinct spiral wear on the lshafting and after a few hours weakensA the'shafting to such an extent that it must beV replaced. The remainder ofthe shafting Arotates within its outer casing` with practically no wiping action thereagainst Vand thewear,- therefore, occurs only near the driven end thereof. Y v

Referring now to Figure 2, it will be'observed that the exible shafting I0 atan approximate point indicated by numeral I5, is deliberately bent or distorted outwardly in aV direction opposite to the spiral bulge normally generated in this portion of the flexible shafting when it is under,

load. It is assumed in Figure 2 and throughout other figures that the flexible shafting is beingv driven in a clockwise direction This distortion,

lis mounted in an oblique or angularbore 20 so .that the end portion of the shaft I0 is not in axial alignment with spindle I.

of the' exible shafting I0 compensates for the eccentric-centrifugal action and, therefore, when rotated at high speed, the portion adjacent the distorted Ypart at I5 is moved or forced into the 5 central portionl of the outer casing, as shown in dotted 1iIles, and the flexible shafting, therefore, does not rub or strike against the casing.

The several other figures of the drawing show different means of accomplishing'the desired result. Thus, in Figure 4, the exible shaft tting Figures' and 6 show the end tting 6 in a bore 2 I which Vis parallel with but eccentric to the true center ofthe vibrator spindle.

- AFigures-'1 andr8 -show still another marmer of accomplishing the desired results in which the flexible' Yshafting I0 terminates and is secured 0 Within .aneccentrically positioned bore -in the socket portion 22of the fitting;

In Figure 9, the flexible shafting terminates 1. A flemme shaft fora concrete' vibrator having an eccentric vweightadapted tobe rotated by a flexible shaft, said shaft being formed of a. spirally wound' wire encased in an outer casing,

o the combination therewith of' aV connection fitting secured to the driven end ofthe shaft, the portion of the said shaft adjacent the said tting Y being laterally distorted in` a direction 'opposite thatgof the `direction of normal distortion of said shaft. Y N j 2. A fiexible shaft for a concrete vibrator having an,eccentricweightradapted to be rotated by va exible shaft, said Weight being mounted on a r q shaft connected to said exible shaft, the portion 5165 of the said shaft adjacent the point of connection with the said weight being laterallyidistorted in adirection opposite thatof the direction ofnormal distortion of said shaft.

3.' A concrete vibrator Vincluding an eccentric 55 weightadapted to be rotated by a flexible shaft,

said weight being mounted on.. a shaft connected to said flexible shaft, and means for bringing the flexible shaft into axial alignment with the vi- ,A brator shaft when the flexible shaft is driven at high speed; said meansl comprising ydistorting the point of Vconnectionuvvith the vibrator shaft in a direction opposite to that` of .the'direction of centrifugal distortion of said flexible.shaft.,

portion ofthe saidV flexible shaft adjacent its 

